Treatment of textile industry wastewater by supported photocatalysis

Photocatalysis with TiO2 particles immobilised either on a glass slide or on a non-woven glass fiber fabric has been applied to pure reactive dyes' (azoïc and metal phthalocyanines) solutions as well as textile wastewater containing the same dyes under UV and solar irradiation. Decolourization of textile wastewater was in the range 21–74% under solar irradiation, with COD removal rate between 0.2 and 0.9 g COD/h/m2. These values are, however, strongly dependent upon the fine chemical structure of the dyes and the global composition of the wastewater. Performance prediction is therefore difficult but the results are encouraging for textile wastewater remediation. The increase of biodegradability is an additional positive factor, as it would improve the efficiency of a biological downstream treatment. No pH adjustment is necessary and wastewater at high pH can be treated directly after suspended solids removal.